Remote coordinate input device and remote coordinate input method

ABSTRACT

The invention prevents an audience from being distracted by movements of a demonstrator that are not related to movements of a pointer on a screen, and by the demonstrator moving away from the screen, during a presentation which is performed by enlarging and projecting the display of a personal computer onto the screen by a projector. A designating tool, which is held by the hand of the demonstrator, is imaged by an imaging part which is disposed at the top of the screen. On the front of the designating tool, infrared LEDs are disposed at each vertex of an isosceles triangle, and recessed at the center, and the orientation of the designating tool is obtained from the positional relationship of the infrared LEDs of an image which has been imaged by the imaging part. This orientation is converted to planar coordinates and is sent to a computer, a marker is displayed on a screen, and the software is operated.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to a remote coordinate input deviceand input method used when either designating a specified portion on ascreen, or operating application software when performing a presentationby projecting an enlarged display of a computer screen onto a screenusing a projector.

[0003] 2. Description of Related Art

[0004] In a conventional presentation, information is displayed on alarge screen by projecting an enlarged display of a transparent-typedocument using an OHP (overhead projector), or by projecting an enlargedfilm image using a slide projector. A demonstrator conducts thepresentation while designating important points of the projected imageusing a pointing stick or a laser pointer.

[0005] Moreover, in recent years, due to the wide distribution ofpersonal computers and liquid crystal projectors, effectivepresentations have been performed using various application softwarethat have been developed for presentations.

[0006] However, a mouse or similar device which is connected to thecomputer must be operated in order to display the screen. In order tooperate the mouse or similar device, the demonstrator must move awayfrom being in front of the screen. Unfortunately, this movement by thedemonstrator and the movement of the pointer on the screen are notrelated to each other. Thus, the audience is sometimes distracted.

[0007] In order to avoid this problem, devices which do not restrict theposition of the demonstrator when the demonstrator is operating thecomputer, and which allow the operator to operate the applicationsoftware by directly operating on the screen from a comparatively freeposition, and which can input so-called remote coordinates are beingdeveloped, and various corresponding methods have also been developed.

[0008] As one example of these methods, Japanese Patent Laid-OpenPublication No. Hei 5-19953 discloses a method of controlling displayedinformation by operating a remote control device from a position whichis distant from the screen. However, the operation is only performed byvarious kinds of keys that are provided on the remote control device.For example, in order to move the pointer on the screen, arrow keys haveto be pressed. However, in this method, the pointer only movesintegratedly, which provides a different feel than one gets frompointing by using a pointing stick.

[0009] Moreover, Japanese Patent Laid-Open Publication No. Hei 2-300816discloses a method in which three light emitting elements are providedon a designating part. Each light emitting element radiates light in adifferent direction. The angle of orientation of the designating part isdetected by the difference in strength of the light received by thelight receiving elements from the light radiated from the light emittingelements. However, since the light has to be modulated in order todistinguish the light emitting elements, the apparatus is subject toproblems, such as the designating part becoming complicated and it beingeasily influenced by external noise because the device uses the lightamount difference.

[0010] Moreover, both of these methods have difficulty in distinguishingbetween two points or more that are simultaneously designated by thedemonstrator and another person, such as someone in the audience.

SUMMARY OF THE INVENTION

[0011] It is therefore an object of the invention to solve theabove-mentioned problems. The remote coordinate input device inaccordance with the invention includes designating means that has atleast three first light emitting elements and a second light emittingelement that is arranged on an orthogonal axis that is perpendicular toa plane delineated by said first light emitting elements, an imagingmeans that images a relative positional relationship of said first andsecond light emitting elements of said designating means, a coordinateconverting means that obtains a direction in which said designatingmeans points with respect to said imaging means from a picture signalwhich is imaged by said imaging means and converts it to a planarcoordinate, an output means that outputs the coordinate that is obtainedby said coordinate converting means, and a display means that displaysdesignating information on a screen based on said coordinate that isobtained by said output means.

[0012] In accordance with another aspect of the remote coordinate inputdevice, said first light emitting elements are respectively arranged ateach vertex of an isosceles triangle, and a base of the triangle whichconnects two of the first light emitting elements is substantiallyhorizontally arranged.

[0013] In accordance with another aspect of the remote coordinate inputdevice, said first light emitting elements are respectively arranged ateach vertex of a rhombus, and one diagonal line of said rhombus issubstantially horizontally arranged.

[0014] Another aspect of the remote coordinate input device furtherincludes a modulating means that modulates said first or second lightemitting elements according to operating information from an operatingmeans that is provided on said designating means, and a light receivingmeans that detects the modulated operating information.

[0015] Another aspect of the remote coordinate input device furtherincludes a hand detecting means that detects whether said designatingmeans is being held by a hand of the user, and controls lighting orturning off of the light of said first and second light emittingelements by an output of said hand detecting means.

[0016] Another remote coordinate input device in accordance with theinvention includes a designating means that has at least three firstreflecting elements and a second reflecting element that is arranged onan orthogonal axis which is perpendicular to a plane delineated by saidfirst reflecting elements, an irradiating means that irradiates saidfirst and second reflecting elements of said designating means, animaging means that images a relative positional relationship of saidfirst and second reflecting elements of said designating means, acoordinate converting means that obtains a direction in which saiddesignating means points with respect to said imaging means from apicture signal that has been imaged by said imaging means, and convertsit into a planar coordinate, an output means that outputs the coordinatethat is obtained by said coordinate converting means, and a displaymeans that displays designating information on a screen based on saidcoordinate that is obtained from said output means.

[0017] In accordance with another aspect of this remote coordinate inputdevice, said first reflecting elements are respectively arranged at eachvertex of an isosceles triangle, and a base of the triangle whichconnects two of the reflecting elements is substantially horizontallyarranged.

[0018] In accordance with another aspect of this remote coordinate inputdevice, said first reflecting elements are respectively arranged at eachvertex of a rhombus and one diagonal line of said rhombus issubstantially horizontally arranged.

[0019] Another remote coordinate input device in accordance with theinvention includes a designating means that has a hollow disk-shapedfirst reflecting element and a second reflecting element which isarranged on an orthogonal axis that is perpendicular to a planedelineated by said first reflecting element, an irradiating means thatirradiates said first and second reflecting elements of said designatingmeans, an imaging means that images a relative positional relationshipof said first and second reflecting elements of said designating means,a coordinate converting means that obtains a direction in which saiddesignating means points with respect to said imaging means from asignal which has been imaged by said imaging means and converts it to aplanar coordinate, an output means that outputs the coordinate that isobtained by said coordinate converting means, and a display means thatdisplays designating information on a screen based on said coordinatethat is obtained by said output means.

[0020] A remote coordinate input method in accordance with the inventionincludes the steps of obtaining a first image with a first lightemitting element or a first reflecting element, obtaining a second imagewith a said second light emitting element or a second reflectingelement, obtaining a reference coordinate from a coordinate of saidfirst image and a direction with respect to an imaging means of adesignating means from the positional relationship of said second imageand said reference coordinate, and specifying a designating position ina display means according to said direction.

[0021] Another aspect of the remote coordinate input method furtherincludes obtaining independent designating tool images in which an imageof a plurality of designating means is separated into independent imagesfrom the image which has been imaged by said imaging means, obtaining adirection with respect to said imaging means of said designating meansfor every independent designating tool image, and specifying adesignated position by said display means according to said directions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a diagram showing a first embodiment of the presentinvention.

[0023]FIG. 2 is a diagram showing one example of a designating tool ofthe first embodiment of the present invention.

[0024]FIG. 3 is a three-face-view explaining the details of a front partof the designating tool of the first embodiment of the presentinvention.

[0025]FIG. 4 is a diagram showing one example of an imaging part of thefirst embodiment of the present invention.

[0026]FIG. 5 is a diagram showing one example of an output image of aCCD camera of the first embodiment and a second embodiment of thepresent invention.

[0027]FIG. 6 is a plan view showing the positions of LEDs of thedesignating tool of the first embodiment of the present invention.

[0028]FIG. 7 is a side view showing positions of the LEDs of thedesignating tool of the first embodiment of the present invention.

[0029]FIG. 8 is a flow chart showing a procedure of obtaining thecoordinates in accordance with the first and second embodiments of thepresent invention.

[0030]FIG. 9 is a diagram showing another example of a designating toolof the first embodiment of the present invention.

[0031]FIG. 10 is a three-face-view showing details of the front part ofthe designating tool of the first embodiment of the present invention.

[0032]FIG. 11 is a diagram showing one example of the output image ofthe CCD camera of the first embodiment of the present invention.

[0033]FIG. 12 is a plan view showing positions of the LEDs of thedesignating tool of the first embodiment of the present invention.

[0034]FIG. 13 is a side view showing positions of the LEDs of thedesignating tool of the first embodiment of the present invention.

[0035]FIG. 14 is a diagram showing the second embodiment of the presentinvention.

[0036]FIG. 15 is a diagram showing one example of a designating tool ofthe second embodiment of the present invention.

[0037]FIG. 16 is a three-face-view showing details of the front part ofthe designating tool of the second embodiment of the present invention.

[0038]FIG. 17 is diagram showing one example of an irradiating part andan imaging part of the second embodiment of the present invention.

[0039]FIG. 18 is a plan view showing the position of the reflectingmembers of the designating tool of the second embodiment of the presentinvention.

[0040]FIG. 19 is a side view showing the position of the reflectingmembers of the designating tool of the second embodiment of the presentinvention.

[0041]FIG. 20 is a diagram showing a third embodiment of the presentinvention.

[0042]FIG. 21 is a diagram showing one example of a designating tool ofthe third embodiment of the present invention.

[0043]FIG. 22 is a three-face-view showing details of the front part ofthe designating tool of the third embodiment of the present invention.

[0044]FIG. 23 is a diagram showing one example of an output image of aCCD camera of the third embodiment of the present invention.

[0045]FIG. 24 is a plan view showing the position of the reflectingmembers of the designating tool of the third embodiment of the presentinvention.

[0046]FIG. 25 is a side view showing the position of the reflectingmembers of the designating tool of the third embodiment of the presentinvention.

[0047]FIG. 26 is a flow chart showing a procedure of obtainingcoordinates of the third embodiment of the present invention.

[0048]FIG. 27 is a flow chart showing a procedure which divides aplurality of images of the designating tool of the first, second, andthird embodiments of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0049] The first embodiment of the present invention is explained basedon the drawings.

[0050]FIG. 1 shows a first embodiment of the present invention. Displaydata of a computer 10 is sent to a projector 4, projected, enlarged, anddisplayed on a screen 7.

[0051] An imaging part 5 is provided at the top of the screen 7. Theimaging part 5 images a designating tool 1, which is held by ademonstrator 9, detects the orientation of the designating tool 1,converts it into coordinates and transfers it to the computer 10. Areceiver 11 is provided at the bottom of the screen 7, which detects aspecified signal from the designating tool 1 and transfers it to thecomputer 10.

[0052] During a presentation, the position of the marker 12 can beshifted by changing the orientation of the designating tool while thedemonstrator 9 is watching the screen.

[0053] The marker 12 is the same as a pointer or a cursor that isoperated by a conventional mouse. When the orientation of thedesignating tool 1 is changed, the marker 12 is shifted, which issimilar to the movement of a pointer or cursor when the mouse is shiftedon its corresponding plane.

[0054] One example of the designating tool 1 is shown in FIG. 2. Aplurality of infrared LEDs (light emitting diodes) 21 that irradiateinfrared rays are provided on a front face. Operating buttons 22 areprovided on a top surface. Hand detecting electrodes 23 are provided ona portion which is held by a hand of the demonstrator. Moreover,batteries, which are not shown in the figure, are housed inside thedesignating tool 1.

[0055]FIG. 3 is a three-face-view which shows details of the front faceof the designating tool 1. The infrared LEDs 21A, 21B and 21C, which arethe first light emitting elements, are disposed in the same plane atvertices of an isosceles triangle. The infrared LEDs 21A and 21B areseparated by a distance “a”. The line connecting LEDs 21A and 21B isparallel to the top surface of the designating tool 1. The infrared LED21C is separated by a distance “b” in the vertical direction from thecenter of the line which connects LEDs 21A and 21B. An infrared LED 21E,which is the second light emitting element, is separated by a distance“b/2” in the vertical direction from 21C in the front face, and isdisposed at a position which is recessed by a distance “d” inside thedesignating tool 1. It is not necessary for LED 21 E to be disposed at aposition on a line which is perpendicular to the plane which isdelineated by LEDs 21A, 21B and 21C. However, compactness of the devicecan be obtained by arranging it as shown in FIG. 3.

[0056] When the demonstrator 9 holds the designating tool 1, a handdetecting electrode 23 detects the fact that the demonstrator 9 isholding the designating tool 1, lights the infrared LEDs 21 (21A, 21B,21C and 21E), and turns the lights off when the demonstrator 9 removeshis or her hand. Moreover, when one of the operating buttons 22 ispressed, the infrared LEDs 21 are all turned off at once, and theinformation of the operating button 22 that is pressed is transmittedvia timed flashes that correspond to a predetermined code of theoperating button 22. The transmitted code is received by the receiver 11and is sent to the computer 10. When the transmission is completed, allthe LEDs are lit again. Moreover, it is possible to assign functions tothe operating buttons 22, such as a function that corresponds to clickbutton of a normal mouse, and a function which corresponds toapplication software which is used in the computer 10.

[0057] Next, one example of the imaging part 5 is shown in FIG. 4. Alens 32 and an infrared ray filter 33 are provided in a CCD camera 31,and an image of the infrared LED 21 of the designating tool 1 is imaged.The output of the CCD camera 31 is connected to an image processor 34.The image processor 34 calculates the planar coordinates on the screen 7based on the image of LED 21 of the designating tool 1 which has beenimaged by the CCD camera 31, and sends the planar coordinates to thecomputer 10 via an output part 35.

[0058] One example of the output image of the CCD camera 31 is shown inFIG. 5. Since the infrared ray filter 33 is disposed in front of thelens 32 of the CCD camera 31, light of interior illuminations or thelike is substantially entirely removed, and only the images 41 from theLEDs 21 are output, as shown in FIG. 5.

[0059] Here, the appearance of images 41 from the designating tool 1 isexplained with reference to the figures.

[0060]FIG. 6 is a plan view in which the LEDs 21 of the designating tool1 are viewed from the top part. The center line 26 connects a midpointbetween the infrared LEDs 21A and 21B, and the lens 32. FIG. 6 shows thecase when the designating tool 1 faces a left diagonal direction by anangle l from the center line 26. When the projection plane 24 is assumedalong lines extending perpendicularly from the center line 26, the spacebetween the infrared LEDs 21A and 21B becomes “x” in the projectionplane 24, and the infrared LED 21E is projected as being shifted by “h”from the center line to the left.

[0061]FIG. 7 is a side view of the LEDs 21 of the designating tool 1.The center line 26 connects a midpoint between the infrarad LEDs 21A,21B and 21C and the lens 32. FIG. 7 shows a case when the designatingtool 1 faces a downward diagonal direction at an angle “m” from centerline 26. When the projection plane 24 is assumed along lines extendingperpendicularly from the center line 26, in the projection plane 24, thespace between the infrared LEDs 21A, 21B and 21C becomes “y”, and theinfrared LED 21E is projected as being shifted upward by a distance “v”from the center line.

[0062] Here, the images 41 which have been imaged by the CCD camera 31can be considered as images which have been imaged at an arbitrarymagnification at the projection plane 24 of FIGS. 6 and 7. Therefore,the images 41 of FIG. 5 have the same geometrical relationships as theprojected images in the projection plane 24. In FIG. 5, images 41A, 41B,41C and 41E are the images of infrared LEDs 21A, 21B, 21C and 21E,respectively. Moreover, the distance between the images 41A and 41B is“X”, the distance from the center of a line which connects 41A and 41Bto the image 41C in the vertical direction is “Y”, the position which isa distance Y/2 above the image 41C is a reference point 42, thehorizontal component of the distance between the image 41E and thereference point 42 is H, and the vertical component of the distancebetween the image 41E and the reference point 42 is V. Since thereference point 42 lies on an extension of the center line 26, eachvalue of x, h, y and v of FIGS. 6 and 7 becomes proportional to therespective value of X, H, Y or V of FIG. 5. Accordingly, when therelationships between images 41A, 41B, 41C and 41E of the images 41 arechecked, it is possible to find out how much the designating tool 1 isinclined horizontally and vertically with respect to the lens 32.

[0063] [Equation 1]

[0064] x=α cos ι

[0065] h=d sin ι${\therefore\frac{h}{x}} = {{{\frac{d}{a}\tan \quad l}\therefore l} = {\tan^{- 1}\left( {\frac{a}{d}\quad \frac{h}{x}} \right)}}$

[0066] [Equation 2]

[0067] y=b cos m

[0068] v=d sin m${\therefore\frac{v}{y}} = {{{\frac{d}{b}\tan \quad m}\therefore\quad m} = {\tan^{- 1}\left( {\frac{b}{d}\quad \frac{v}{y}} \right)}}$

[0069] Equation 1 is an equation which shows the relationship of ahorizontal direction of the projection plane 24. Moreover, equation 2 isan equation which shows the relationship of a vertical direction of theprojection plane 24. As described above, each value of x, h, y and is vis proportional to each respective value of X, H, Y and V. ThereforeEquations 1 and 2 can be described as Equation 3 as follows:

[0070] [Equation 3]$l = {\tan^{- 1}\left( {\frac{a}{d}\quad \frac{H}{X}} \right)}$$m = {\tan^{- 1}\left( {\frac{b}{d}\quad \frac{V}{Y}} \right)}$

[0071] Here, since the values of a, b and d are already known values ofthe designating tool 1, the angles l and m can be obtained from theimages 41 of FIG. 5.

[0072] Moreover, the data which is output to the computer 10 from theoutput part 35 provides horizontal and vertical orthogonal coordinatesof the plane which is projected onto the screen 7. Therefore, when thecenter of the screen is the point of origin, as shown in Equation 4, theangles l and m can be converted into the coordinates Xs, Ys.

[0073] [Equation 4] $\begin{matrix}{{Xs} = {K\quad \tan \quad l}} \\{= {K\quad \frac{a}{d}\quad \frac{H}{X}}}\end{matrix}$ $\begin{matrix}{{Ys} = {K\quad \tan \quad m}} \\{= {K\quad \frac{b}{d}\quad \frac{V}{Y}}}\end{matrix}$

[0074] Here, K of Equation 4 is a proportional constant and is a valueto determine an inclination of the designating tool 1 and thesensitivity of the output. This value can be fixed as an appropriatevalue which is easy to use, or can be set corresponding to thepreference of the demonstrator 9. Moreover, as demonstrated by Equation4, the values of the angles l and m do not need to be obtained in theactual calculation.

[0075] Next, according to the above-mentioned principles, in the imageprocessing device, a method of obtaining coordinates on the screen whichare designated by the designating tool 1 from the image 41 imaged by theCCD camera 31 is explained with reference to the flowchart of FIG. 8.

[0076] In S1, the center of balance coordinate of the images 41A, 41B,41C and 41E is obtained. This is to determine an approximately centeredposition as a representative point since the image has a limited size,and it can be obtained by a commonly known calculation method. Moreaccurate coordinates can be calculated when the center of balancecoordinates are determined when considering the difference of brightnessdue to the distance of each LED from the imaging part being slightlydifferent.

[0077] In S2, the distance X of the horizontal direction and anintermediate coordinate between 41A and 41B are obtained from the centerof balance coordinates of images 41A and 41B.

[0078] In S3, the distance Y of the vertical direction and thecoordinate of the reference point 42, which is the midpoint of both thedistance X and the distance Y, are obtained from the coordinates whichwere obtained in S2 and the center of balance coordinates of the image41C.

[0079] In S4, the center position of image 41E, and the horizontaldistance H and the vertical distance V of the reference point 42 areobtained.

[0080] In S5, the coordinates Xs and Ys on the screen 7 are obtained byEquation 4.

[0081] In summary, a method of obtaining the above-mentioned coordinatesincludes the steps of obtaining the distances X and Y and the referencepoint 42 from the images 41 A, 41B and 41C of the infrared LEDs 21A, 21Band 21C, which are the first light emitting elements of the designatingtool 1, obtaining horizontal and vertical distances H and V of thereference point 42 from the image 41E of the infrared LED 21E, which isthe second light emitting element, and obtaining the coordinates Xs andYs on the screen 7 by a calculation.

[0082] Moreover, here, the center position is the point of origin of thecoordinates on the screen. However, it is possible to make a peripheralpart of the screen the point of origin by providing a bias value.

[0083] The case of using only one designating tool 1 is explained above.However, a method of obtaining the coordinates on the screen designatedby respective designating tools when a plurality of designating toolsare simultaneously used is explained below with reference to theflowchart of FIG. 27.

[0084] In S1, the image is enlarged and processed for each image. It isacceptable to perform processing to fill in the periphery of the portionin which the image exists with the same signal in accordance with apredetermined size.

[0085] Next, in S2, the area of the image for each designating tool isobtained by performing segmentation.

[0086] Since an area of the image for every designating tool is obtainedas stated above, it is acceptable to obtain a coordinate in the area foreach image with reference to the flowchart which is shown in FIG. 8.

[0087] Next, another example of the designating tool 1 is shown in FIG.9.

[0088] A plurality of infrared LEDs (light emitting diodes) 51 thatirradiate infrared rays are provided in the front face of thedesignating tool. Operating buttons 52 are provided on the top surfaceof the designating tool. A hand detecting switch 53 is provided on theportion which is held by the demonstrator's hand. Moreover, batteries,which are not shown in the figure, are housed inside the designatingtool.

[0089]FIG. 10 is a three-face-view which shows the details of the frontface portion of the designating tool. The infrared LEDs 51A, 51B, 51Cand 51D, which are the first light emitting elements, are disposed in arhombus in the same plane. The infrared LEDs 51B and 51D are separatedby a distance “a”. A line that connects LEDs 51B and 51D is parallel tothe top surface at the demonstrator's hand side of the designating tool1. Infrared LEDs 51A and 51C are separated by a distance “b” in thevertical direction. The infrared LED 51E, which is the second lightemitting element, is disposed at a position which is recessed inside thedesignating tool housing by distance “d” at the intersection of astraight line which connects LEDs 51B and 51C and a straight line whichconnects LEDs 51A and 51C in the front view.

[0090] When the demonstrator 9 holds the designating tool 1, the handdetecting switch 53 detects the fact that the demonstrator 9 is holdingthe designating tool in his or her hand, lights the infrared LEDs 51(51A, 51B, 51C, 51D and 51E), and turns them off when the demonstrator 9removes his or her hand from the designating tool. Moreover, when theoperating button 52 is pressed, the infrared LEDs 51 are all turned offat once, and information of operation button 52 that is pressed istransmitted via timed flashes that correspond to a predetermined code ofthe operation button 52. The transmitted code is received by thereceiver 11 and is sent to the computer 10. When the transmission iscompleted, all the infrared LEDs are lit again. Moreover, the operationbuttons 52 may be assigned the function of a click button of a normalmouse, a function which corresponds to application software which isused in the computer 10, or another function.

[0091] Here, the imaging of images 61 that are transmitted by thedesignating tool 1 is explained with reference to the figures.

[0092]FIG. 12 is a plan view in which the LEDs 51 of the designatingtool are viewed from the top. The center line 56 is a straight linewhich connects a midpoint between the infrared LEDs 51B and 51D, and thelens 32. FIG. 12 shows the case when designating tool 1 faces a leftdiagonal direction at an angle l from the center line 56. When theprojection plane 54 is assumed along lines extending perpendicularlyfrom the center line 56, the space between the infrared LEDs 51B and 51Dbecomes “x” in the projection plane 54, and the infrared LED 51E isprojected as being shifted by a distance “h” from the center line to theleft.

[0093]FIG. 13 is a side view in which the LED 51 of the designating tool1 is viewed from the side. The center line 56 connects a midpointbetween the infrared LEDs 51A and 51C, and the lens 32. FIG. 13 shows acase when the designating tool 1 faces a downward diagonal direction atan angle “m” from the center line 56. When the projection plane 54 isassumed along lines extending perpendicularly from the center line 56,in the projection plane 54, the space between the infrared LEDs 51A and51C becomes “y”. Moreover, the infrared LED 51E is projected as beingshifted upward by a distance “y” from the center line.

[0094] Here, one example of the images 61 which are imaged by the CCDcamera 31, is shown in FIG. 11. The image 61 can be considered as animage at an arbitrary magnification at the projection plane 54 of FIGS.12 and 13. Therefore, the images 61 of FIG. 11 have the same geometricalrelationships as the projected images in the projection plane 54. InFIG. 11, the images. 61A, 61B, 61C, 61D and 61E are the imagestransmitted by the infrared LEDs 51A, 51B, 51C, 51D and 51E,respectively. Moreover, the space between images 61B and 61D is “X”, thespace between 61A and 61C is “Y”, the intersection of a straight linewhich connects the images 61B and 61D and a straight line which connectsthe images 61A and 61C is a reference point 62, the horizontal componentof the distance between the reference point 62 and the image 61E is “H”,and the vertical component is “V”. The reference point 62 lies on anextension of the center line 56. Therefore, each value of x, h, y and vof FIGS. 12 and 13 becomes proportional to the respective value of X, H,Y and V of FIG. 11. Accordingly, when the relationships of the images61A, 61b, 61C, 61D and 61E are checked, it is possible to find out howmuch the designating tool 1 is inclined horizontally and vertically withrespect to the CCD camera 31.

[0095] Accordingly, even when the infrared LEDs 51A, 51B, 51C and 51Dare disposed at the vertices of a rhombus, it can be treated similar tothe case of when the aforementioned infrared LEDs 21A, 21B and 21C aredisposed at the vertices of an isosceles triangle, and the coordinateson the screen can be used by using the same method.

[0096] Moreover, in the present embodiment, the case is described wherethe center infrared LED of the designating tool is positioned deeperinside the designating tool than the surrounding infrared LEDs.Furthermore, another example of this apparatus, wherein the centerinfrared LED protrudes outwardly with respect to the surroundinginfrared LEDs, can be treated the same way by merely reversing thepolarity of the output coordinates.

[0097] In the present embodiment, a method of independently obtainingangles in the horizontal and vertical planes is shown. However, whenboth planes are inclined, the angles which appear in the plan and sideviews are slightly shifted from the accurate values. Moreover,technically, error occurs when the designating tool is rotated. However,according to the present embodiment, the designating tool is operatedwhile the operator watches the marker which is displayed on the screen.Thus, the result of the operation is instantly apparent, so that minorerrors do not actually cause problems.

[0098] A second embodiment of the present invention is explained withreference to the drawings.

[0099]FIG. 14 shows the second embodiment of the present invention. Thedisplay data of the computer 10 is sent to the projector 4, projected,enlarged and displayed on screen 8. The screen 8 is a rear type screen,wherein the side of the screen that is viewed is on the opposite side ofthe screen from the side that is projected onto by the projector 4.

[0100] At the top of the screen 8, an imaging part 5 and an illuminatingpart 6 are provided together in a single unit, which irradiates infraredlight to a front surface of the designating tool 2 and images thereflected image, detects the orientation of the designating tool 2,converts the orientation into coordinates and transfers the coordinatesto the computer 10.

[0101] During a presentation or the like, the position of the marker 12can be shifted by the demonstrator 9 by changing the orientation of thedesignating tool 2 while watching the screen.

[0102] The marker 12 is the same as a pointer or cursor that is operatedby a conventional mouse. The marker 12 can be shifted when theorientation of the designating tool 2 is changed, similar to a pointerand cursor being shifted when the mouse is shifted on a correspondingflat surface.

[0103] One example of the designating tool 2 is shown in FIG. 15. Aplurality of reflecting members 71 that reflect infrared rays areprovided on the front face of the designating tool 2.

[0104]FIG. 16 is a three-face-view which shows details of the front faceportion of the designating tool 2. The reflecting members 71A, 71B and71C, which are the first reflecting elements, are disposed in the sameplane at the vertices of an isosceles triangle. The reflecting members71A and 71B are separated by a distance “a”. A line that connectsmaterials 71A and 71B is parallel to the top surface of the designatingtool 2. The reflecting member 71C is separated by a distance “b” in thevertical direction from the center of a line which connects reflectingmaterials 71A and 71B. The reflecting member 71E, which is the secondreflecting element, is disposed at a position which is recessed by adistance “d” within the designating tool, separated by a distance b/2 inthe vertical direction from 71C in the front view.

[0105] One example of the imaging part 5 and the illuminating part 6 isshown in FIG. 17. The illuminating part 6 has a structure in which manyinfrared LEDs 36 are disposed around the lens 32 of the CCD camera 31,and irradiates in the direction which is imaged by the imaging part 5.Moreover, the imaging part 5 includes the CCD camera 31, the lens 32,the infrared ray filter 33, the image processor 34, and the output part35. The lens 32 and the infrared ray filter 33 are disposed on the CCDcamera 31, and an image of the reflecting member 71 of the designatingtool 2 is imaged. The output of the CCD camera 31 is connected to theimage processor 3,4. The image processor 34 calculates the planarcoordinates on the screen 8 based on the image of the reflecting member71 of the designating tool 2 which has been imaged by the CCD camera 31,and sends it to the computer 10 via the output part 35.

[0106] One example of the output image of the CCD camera 31 is shown inFIG. 5. Since the infrared ray filter 33 is disposed in front of thelens 32, the light of interior room illuminations or the like aresubstantially eliminated, as shown in FIG. 5, and only images 41transmitted by the reflecting member 71 are output.

[0107] Here, the transmitting of the images 41 by the designating tool 2is explained with reference to the figures.

[0108]FIG. 18 is a plan view in which the reflecting member 71 of thedesignating tool 2 is viewed from the top. The center line 76 connects amidpoint between the reflecting members 71A and 71B and the lens 32.FIG. 18 shows the case when the designating tool 2 faces a left diagonaldirection at an angle l from the center line 76. When the projectionplane 74 is assumed on lines extending perpendicularly from the centerline 76, in the projection plane 74, the space between the reflectingmember 71A and 71B becomes “x”, and the reflecting member 71E is shiftedto the left by a distance “h” from the center line and is projected.

[0109]FIG. 19 is a side view in which the reflecting member 71 of thedesignating tool 2 is viewed from the side. The center line 76 connectsthe midpoint between the reflecting members 71A, 71B and 71C and thelens 32. FIG. 19 shows a case when the designating tool 2 faces thedownward diagonal direction at an angle m from the center line 76. Whenthe projection plane 74 is assumed on lines extending perpendicularlyfrom the center line 76, in projection plane 74, the distance betweenthe reflecting member 71A, 71B and 71C becomes “y”, and the reflectingmember 71E is shifted upwards by a distance “v” from the center line andis projected.

[0110] Here, the images 41 which have been imaged by the CCD camera 31can be considered as images which are imaged at an arbitrarymagnification at projection plane 74 of FIGS. 18 and 19. Thus, theimages 41 of FIG. 5 have the same geometrical relationship as theprojected images in the projection plane 74. In FIG. 5, the images 41A,41B, 41C, and 41E are the images of the reflecting members 71A, 71B,71C, and 71E, respectively. Furthermore, the distance between the image41A and 41B is defined as “X”, the distance between the center of theline connecting 41A with 41B and the image 41C in a vertical directionis defined as “Y”, and the position which is above the image 41C by Y/2is defined as a reference point 42. The horizontal component of thedistance between the reference point 42 and the image 41E is defined as“H”, and the vertical component of the distance between the image 41Eand the reference point 42 is defined as “V”. Because the referencepoint 42 lies on an extension of the center line 76, each value of x, h,y and v of FIGS. 18 and 19 has a proportional relationship to therespective value of X, H, Y or V of FIG. 5. Therefore, if therelationships of the images 41A, 41B, 41C, and 41E to the images 41 arechecked, it is possible to determine how much designating tool 2 isinclined in the horizontal and vertical directions with respect to theCCD camera 31. Ps [Equation 5]

[0111] x=α cos ι

[0112] h=d sin ι${\therefore\frac{h}{x}} = {{{\frac{d}{a}\tan \quad l}\therefore l} = {\tan^{- 1}\left( {\frac{a}{d}\quad \frac{h}{x}} \right)}}$

[0113] [Equation 6]

[0114] y=b cos m

[0115] v=d sin m${\therefore\frac{v}{y}} = {{{\frac{d}{b}\tan \quad m}\therefore\quad m} = {\tan^{- 1}\left( {\frac{b}{d}\quad \frac{v}{y}} \right)}}$

[0116] Equation 5 is a formula showing the relationship in thehorizontal direction in the projection plane 74. Furthermore, Equation 6is a formula showing the relationship in the vertical direction in theprojection plane 74. As described earlier, each value of x, h, y, and vhas a proportional relationship with the respective value of X, H, Y, orV, so Equations 5 and 6 can be defined as Equation 7, which will beshown as follows.

[0117] [Equation 7]$l = {\tan^{- 1}\left( {\frac{a}{d}\quad \frac{H}{X}} \right)}$$m = {\tan^{- 1}\left( {\frac{b}{d}\quad \frac{V}{Y}} \right)}$

[0118] Here, because the values of a, b, and d of the designating tool 1are already-known values, angles l and m can be obtained from the images41 of FIG. 5.

[0119] Furthermore, the data which is output to the computer 10 from theoutput part 35 provide horizontally and vertically orthogonalcoordinates of the plane which is projected onto the screen 8.Therefore, if the center of the screen is the point of origin, as shownin Equation 8, the angles l and m can be converted to the coordinatesXs, Ys.

[0120] [Equation 8] $\begin{matrix}{{Xs} = {K\quad \tan \quad l}} \\{= {K\quad \frac{a}{d}\quad \frac{H}{X}}}\end{matrix}$ $\begin{matrix}{{Ys} = {K\quad \tan \quad m}} \\{= {K\quad \frac{b}{d}\quad \frac{V}{Y}}}\end{matrix}$

[0121] Here, K of Equation 8 is a proportional constant and is a valueto determine sensitivity of output and the inclination of thedesignating tool 1. This value can be fixed at an appropriate valuewhich can be easily used, or can be set in response to the preference ofthe demonstrator 9. Furthermore, as understood from Equation 8, thevalues of angles l and m do not need to be obtained in the actualcalculation.

[0122] Next, according to the above image processor 34, a method ofobtaining the coordinates on the screen which are transmitted by thedesignating tool 1 to form the images 41 which are imaged by the CCDcamera 31 is explained by the flow chart of FIG. 8.

[0123] In S1, the center of balance coordinates of each of the images41A, 41B, 41 C, and 41E are obtained in order to determine asubstantially center position as a representative point, because theimages have a limited size. The center position can be obtained by acommonly known calculation method.

[0124] In S2, the distance X in the horizontal direction and anintermediate coordinate between the images 41A and 41B are obtained fromthe center of balance coordinates of the images 41A and 41B.

[0125] In S3, the distance Y in the vertical direction and thecoordinates of the reference point 42, which is the midpoint of both thedistance X and the distance Y, are obtained from the center of balancecoordinates of the image 41C and the intermediate coordinate which wasobtained in S2.

[0126] In S4, the center position of image 41E and the horizontaldistance H and the vertical distance V of the reference point 42 areobtained.

[0127] In S5, the coordinates Xs, Ys on the screen 8 are obtained byEquation 8.

[0128] In summary, a method of obtaining the above coordinates, thedistances X, Y and the reference point 42, are obtained from the images41A, 41B, and 41C of the reflecting members 71A, 71B, and 71C, which arethe first reflecting elements of the designating tool 2, the horizontaland vertical distances H, V of the reference point 42 are obtained fromthe image 41E of the reflecting member 71E, which is the secondreflecting element, and the coordinates Xs, Ys on a screen are obtainedby the above calculation.

[0129] Furthermore, the coordinates on the screen 8 use the center asthe point of origin. However, it is possible to use a peripheral part ofthe screen as the point of origin by setting a bias value.

[0130] The case where only one designating tool 2 is used is explainedabove. However a method of obtaining the coordinates on the screendesignated by respective designating tools when a plurality ofdesignating tools are simultaneously used is explained by the flowchartof FIG. 27.

[0131] In S1, the image is enlarged and processed for each image. It ispreferable to perform a processing to fill in the periphery of the partin which the image exists by the same signal at a predetermined size.

[0132] Next, in S2, the image area is obtained for each designating toolby performing segmentation.

[0133] Since an image area is thus obtained for each designating tool,the coordinates may be obtained by the flow chart explained in FIG. 8for the respective image ranges.

[0134] The above invention is explained based upon the embodiment of thedesignating tool 2 shown in FIG. 19. However, as another example of theinvention, it is also possible to perform the same processing as is donewith LEDs by replacing the LEDs 51A, 51B, 51C, 51D, and 51E explained inembodiment 1 with reflecting members.

[0135] Thus, even when the reflecting members are disposed at thevertices of a rhombus, it is possible to operate in the same manner asthe case in which the reflecting members 71A, 71B, and 71C are disposedin the shape of an isosceles triangle. Thus, it is possible to obtainthe coordinates on the screen by the same method.

[0136] Furthermore, in the present embodiment, the case is explained inwhich the center reflecting member of the designating tool 2 is disposedbehind the surrounding reflecting members. However, as another exampleof the invention, when the center reflecting member protrudes outwardlywith respect to the surrounding reflecting members, it is possible tooperate in the same manner by merely reversing the polarity of theoutput coordinates.

[0137] Furthermore, the method of independently obtaining angles in thehorizontal and vertical planes is shown in the present embodiment.However, when both the horizontal and vertical planes are inclined, theangles which will be shown in the plan and side views are technicallydifferent from accurate values. Furthermore, errors also technicallyoccur when the designating tool is rotated. However, in the case of thepresent embodiment, when the designating tool is operated while watchingthe marker which is displayed on the screen, the result of the operationis instantly apparent, so that these errors do not cause a problem.

[0138] In addition, a structure in which the imaging part 5 and theilluminating part 6 are integrated is explained in the presentembodiment. However, it is also possible to install them in separatelocations.

[0139] The third embodiment of the present invention is explained basedupon the figures.

[0140]FIG. 20 shows the third embodiment of the present invention. Thedisplay data of a computer 10 is sent to a projector 4, and theprojected image is reflected against a mirror 13, is enlarged, and isdisplayed on a screen 8. The screen 8 is a rear type screen, wherein thesurface that is observed is on the opposite side as the surface that isprojected onto by the projector 4. Additionally, the projector 4, themirror 13, and the computer 10 are stored in a case 14, and theseelements, collectively, except the computer 10, can be referred to as arear projector.

[0141] The imaging part 5 and an illuminating part 6 are integrated anddisposed at the bottom of the screen 8. The reflected image is imaged asinfrared light, and is irradiated in front. The direction of thedesignating tool 3 is detected, converted into coordinates, and istransmitted to the computer 10.

[0142] During a presentation or the like, the demonstrator 9 can movethe position of the marker 12 by changing the orientation of thedesignating tool 3 while watching the screen.

[0143] The marker 12 is the same as the pointer or cursor which isoperated by a conventional mouse. It is possible to move the marker 12by changing the orientation of the designating tool 3 in the same mannerthat the pointer or cursor is moved by moving the mouse on acorresponding flat surface.

[0144] One example of the designating tool 3 is shown in FIG. 21. Aplurality of reflecting members 81 which reflect infrared radiation, aredisposed on the front face of the designating tool.

[0145]FIG. 22 is a three-face-view showing the front face of thedesignating tool 3 in detail. The reflecting members 81 comprise areflecting member 81A, which is the first reflecting element, and areflecting member 81B, which is the second reflecting element. Thereflecting member 81A is in the shape of a ring, wherein the centerdiameter is a distance “a”, and the reflecting member 81B is disposed inthe center, protruding outward by a distance “d”.

[0146] One example of the imaging part 5 and the illuminating part 6 isshown in FIG. 17. The illuminating part 6 has a structure in which manyinfrared LEDs 36 are disposed at the periphery of the lens 32 of the CCDcamera 31, and irradiate in the direction which is imaged by the imagingpart 5. Additionally, the imaging part 5 includes the CCD camera 31, thelens 32, the infrared ray filter 33, the image processor 34, and theoutput part 35. The lens 32 and the infrared ray filter 33 are attachedto the CCD camera 31, and the image of the reflecting members 81 of thedesignating tool 3 is imaged. The output of the CCD camera 31 isconnected to the image processor 34. The image processor 34 calculatesthe planar coordinates on the screen 8, based upon the image of thereflecting members 81 of the designating tool 3 which have been imagedby the CCD camera 31, and outputs them to the computer 10 via the outputpart 35.

[0147] One example of an output image of the CCD camera 31 is shown inFIG. 23. Because the infrared ray filter 33 is fixed in front of thelens 32 of the CCD camera 31, light such as room illumination can besubstantially eliminated, and only the image 91 of the reflectingmembers 81 is output, as shown in FIG. 23.

[0148] Here, the transmitting of the images 91 by the designating tool 3is explained by the diagrams.

[0149]FIG. 24 is a plan view of the reflecting members 81, as seen fromthe top by cutting the designating tool 3 in a horizontal plane throughits center. The center line 86 is a line connecting the center of thereflecting member 81A with the lens 32. FIG. 24 shows the case when thedesignating tool 3 is inclined from the center line 86 at an angle l inthe left diagonal direction. If the projection plane 84 is assumed alonglines extending perpendicularly from the center line 86, the interval ofthe reflecting member 81A in the projection plane 84 in the diameterdirection is “x”, and the reflecting member 81B is shifted to the leftfrom the center line by a distance “h” and s projected.

[0150]FIG. 25 is a side view of the reflecting members 81 by cutting thedesignating tool 3 along a vertical plane through its center. The centerline 86 is a line connecting the center of the reflecting member 81Awith the lens 32. FIG. 25 shows the case when the designating tool 3faces a downward diagonal direction from the center line 86 at an anglem. If the projection plane 84 is assumed along lines extendingperpendicularly from the center line 86, the interval of the reflectingmember 81A in the diameter direction is “y” in the projection plane 84,and the reflecting member 81B is shifted in an upper direction by adistance “y” from the center line and is projected.

[0151] Here, the images 91 which are imaged by the CCD camera 31 can beconsidered as images which are imaged at an arbitrary magnification atthe projection plane 84 of FIGS. 24 and 25. So the images 91 of FIG. 23have the same geometrical relationship as the projected images in theprojection plane 84. In FIG. 23, the images 91A and 91B are images ofthe reflecting members 81A and 81B, respectively. Furthermore, themaximum interval of the image 91A in the horizontal direction is definedas “X”, the maximum interval in the vertical direction is defined as“Y”, and the crossing point of vertical and horizontal lines whichtravel through the center of the respective intervals is defined as thereference point 92. Furthermore, the horizontal component of thedistance between the reference point 92 and the image 91B is defined as“H”, and the vertical component is defined as “V”. Because the referencepoint 92 lies on an extension of the center line 86, each value of x, h,y, and v of FIGS. 24 and 25 has a substantially proportionalrelationship to the respective value of X, H, Y, or V of FIG. 23.Accordingly, if the relationships of images 91A and 91B of the images 91are checked, it is possible to determine how much the designating toolis inclined in the horizontal and vertical directions with respect tothe CCD camera 31.

[0152] [Equation 9]

[0153] x=α cos ι

[0154] h=d sin ι${\therefore\frac{h}{x}} = {{{\frac{d}{a}\tan \quad l}\therefore l} = {\tan^{- 1}\left( {\frac{a}{d}\quad \frac{h}{x}} \right)}}$

[0155] [Equation 10]

[0156] y=α cos m

[0157] v=d sin m${\therefore\frac{v}{y}} = {{{\frac{d}{b}\tan \quad m}\therefore\quad m} = {\tan^{- 1}\left( {\frac{b}{d}\quad \frac{v}{y}} \right)}}$

[0158] Equation 9 is a formula showing the relationship in thehorizontal direction of the projection plane 84. Furthermore, Equation10 is a formula showing the relationship in the vertical direction ofthe projection plane 84. As described earlier, each value of x, h, y,and v has a substantially proportional relationship to the respectivevalue of X, H, Y, or V of FIG. 23, so Equations 9 and 10 can be definedas Equation 11 which will be shown below.

[0159] [Equation 11]$l = {\tan^{- 1}\left( {\frac{a}{d}\frac{H}{X}} \right)}$$m = {\tan^{- 1}\left( {\frac{a}{d}\frac{V}{Y}} \right)}$

[0160] Here, the values of a, d are already-known values of thedesignating tool 3, so the angles l and m can be obtained from theimages 91 of FIG. 23.

[0161] Furthermore, the data which is output to the computer 10 from theoutput part 35 provides horizontally and vertically orthogonalcoordinates of the plane which is projected onto the screen 8.Therefore, if the center of the screen is the point of origin, it ispossible to convert the angles l and m to the coordinates Xs, Ys, asshown in Equation 12.

[0162] [Equation 12] $\begin{matrix}{X_{S} = {K\quad \tan \quad l}} \\{= {K\frac{a}{d}\frac{H}{X}}}\end{matrix}$ $\begin{matrix}{Y_{S} = {K\quad \tan \quad m}} \\{= {K\frac{a}{d}\frac{V}{Y}}}\end{matrix}$

[0163] Here, K of Equation 12 is a proportional constant and is a valueto determine the sensitivity of output and the inclination of thedesignating tool 3. This value can be fixed at an appropriate valuewhich can be easily used, or can be set in response to the preference ofthe demonstrator 9. Furthermore, as understood from Equation 12, thevalues of angles l, m do not need to be obtained in the actualcalculation.

[0164] Next, in accordance with the image processor 34, a method ofobtaining coordinates on the screen which are designated by thedesignating tool 3 from the images 91 which have been imaged by the CCDcamera 31 is explained by the flowchart of FIG. 26.

[0165] In S1, the positions of the right and left edges of the image 91Ain the horizontal direction are obtained, the center of balancecoordinates in the horizontal direction of each edge part are obtained,and the distance X between both edge parts in the horizontal directionis obtained.

[0166] In S2, the positions of the upper and lower edges of the image91A in the vertical direction are obtained, the center of balancecoordinates in the vertical direction of each edge part are obtained,and the distance Y between both edge parts in the vertical direction isobtained.

[0167] In S3, the coordinates of the reference point 92, which is at thecenter position of both X and Y, respectively, are obtained.

[0168] In S4, the center of balance coordinate of the image 91B isobtained, and the distance between the image 91B and the coordinates ofthe reference point 92 is obtained as H in the horizontal direction andas V in the vertical direction.

[0169] In S5, the coordinates Xs, Ys on the screen are obtained byEquation 12.

[0170] In summary, in accordance with the method of obtaining the abovecoordinates, the distances X, Y and the reference point are obtainedfrom the image 91A of the reflecting member 81A, which is the firstreflecting element of the designating tool 3, the horizontal andvertical distances H, V between the reference point and the image 91B ofthe reflecting member 91B, which is the second reflecting element, areobtained, and the coordinates Xs, Ys on the screen are obtained by acalculation.

[0171] Furthermore, the coordinates on the screen use the center as thepoint of origin, but it is possible to use the periphery of the screenas the point of origin by setting a bias value.

[0172] The case in which only one designating tool 3 is used has beenexplained above. However, a method for obtaining the coordinates on thescreen designated by respective designating tools when a plurality ofdesignating tools are simultaneously used is explained by the flowchartof FIG. 27.

[0173] In S1, the image is enlarged and processed for each image. It ispreferable to fill in the periphery of the part in which the imageexists by the same signal at a predetermined size.

[0174] Next, in S2, the image area is obtained for each designating toolby performing segmentation.

[0175] Because the image area is thus obtained for the designating tool,the coordinates can be obtained by the flow chart explained in FIG. 26with regard to the respective image areas.

[0176] As explained above, in the present embodiment, the case in whichthe reflecting member at the center of the designating tool 3 protrudesoutwardly with respect to the reflecting member at the periphery isexplained. However, as another example of the invention, when thereflecting member at the center is positioned behind the reflectingmember at the periphery, it is possible to operate in the same manner bymerely reversing the polarity of the output coordinates.

[0177] Furthermore, a method for obtaining angles independently in thehorizontal and vertical planes is shown in the present embodiment, andwhen both planes are inclined, the angle which appears in the plan andside views is technically not accurate. However, as in the presentembodiment, when the demonstrator operates the designating tool whilewatching the marker which is displayed on the screen, the operationresult is instantly apparent, so that minor errors do not cause aproblem.

[0178] As explained above, according to the present invention, thedesignating tool includes at least three light emitting elements and alight emitting element which is located on an orthogonal axis to a planedelineated by the at least three light emitting elements, the relativepositional relationship of the light emitting elements is imaged by animage pick-up means, and the orientation in which the designating toolpoints toward the image pick-up means is obtained from the image signaland is converted to planar coordinates. Therefore, it is possible to useapplication software of the computer by moving the marker on the screenas the demonstrator moves the designating tool. Because of this, it ispossible for the demonstrator to explain items by pointing them out, asif with a laser pointer, without having to move from in front of thescreen during a presentation where a computer screen is enlarged andprojected by a projector. Therefore, it is possible to prevent theaudience from being distracted.

[0179] Furthermore, light emitting elements are disposed at each vertexof an isosceles triangle, and the base of the triangle connecting two ofthe light emitting elements is substantially horizontally disposed, sosquare and/or root calculations are not needed in order to obtain thediagonal distance and coordinates. Therefore, it is possible to simplifythe calculation to obtain the coordinates from the image which has beenimaged.

[0180] Furthermore, light emitting elements are disposed at each vertexof a rhombus, and one diagonal line of the diagonal shape issubstantially horizontally disposed, so the square and/or rootcalculations are not needed in order to obtain the diagonal distance andcoordinates. Thus, it is possible to simplify the calculation to obtainthe coordinates from the image which has been imaged.

[0181] Furthermore, a modulating means to modulate the light emittingelements in accordance with the operating information from the operatingmeans and a light receiving means to detect the modulated operatinginformation are provided, so it is possible to operate applicationsoftware the same way as is done with a mouse, and operations such aspage scrolling or the like can be performed, using only the designatingtool, during the presentation, and distraction of the flow of thepresentation can be avoided.

[0182] In addition, a hand detecting means is provided on thedesignating tool, and turning on and off of the light emitting elementscan be controlled, so that it is possible to turn the lights off when itis not being used, and turn the lights on when it is being used. Thus,it is possible to avoid wasting energy, such as batteries, and to have along life expectancy of the light emitting elements.

[0183] Furthermore, the designating tool includes at least threereflecting elements and a reflecting element which is disposed on anorthogonal axis to a plane delineated by the at least three lightemitting elements, the relative positional relationship of thereflecting elements irradiated by an irradiating means is imaged by animage pick-up means, and the direction in which the designating toolpoints with respect to the image pick-up means is obtained from theimage signal and is converted to planar coordinates. Therefore, it ispossible to use application software of a computer by moving a marker onthe screen as the demonstrator moves the designating tool. Because ofthis, it is possible for the demonstrator to explain items by pointingthem out, as if with a laser pointer, without having to leave the viewof the audience during a presentation performed by enlarging the imageonto a computer screen and projecting it with a projector. Thus, it ispossible to prevent the audience from being distracted. Furthermore, thedesignating tool does not need an energy source, such as a battery, somaintenance management can be easily performed.

[0184] Furthermore, the reflecting elements are disposed at each vertexof an isosceles triangle, and the base of the triangle connecting two ofthe reflecting elements is substantially horizontally disposed, sosquare and/or root calculations are not needed in order to obtain thediagonal distance and coordinates. Thus, it is possible to simplify thecalculation in order to obtain the coordinates from the image which hasbeen imaged.

[0185] In addition, the reflecting elements are disposed at each vertexof a rhombus, and one diagonal line of the rhombus is substantiallyhorizontally disposed, so square and/or root calculations are not neededin order to obtain the diagonal distance and coordinates. Thus, it ispossible to simplify the calculation to obtain the coordinates from theimage which has been imaged.

[0186] Furthermore, the designating tool includes a reflecting elementof a hollow disk shape which is disposed in a single plane, and areflecting element which is disposed on an orthogonal axis to the planedelineated by the disk-shaped reflecting element, the relativepositional relationship of the reflecting devices which have beenirradiated by an irradiating means is imaged by an imaging means, andthe direction in which the designating tool points with respect to theimaging means is obtained from the image signal and is converted toplanar coordinates. Therefore, it is possible to use the applicationsoftware of the computer by moving the marker on the screen as thedemonstrator moves the designating tool. Because of this, it is possiblefor the demonstrator to explain items by pointing them out, as if with alaser pointer, without having to leave the view of the audience during apresentation or the like in which an image of a computer screen isenlarged and projected by the projector. Therefore, it is possible toprevent the audience from being distracted. Furthermore, the designatingtool does not need an energy source, such as a battery, so themaintenance management can be easily performed. In addition, thereflecting element of the designating tool is radially symmetrical, soit is possible to use the designating tool regardless of the manner inwhich the demonstrator holds the designating tool.

[0187] Furthermore, in a method of the invention, a first image from thefirst light emitting element or the first reflecting element and asecond image from the second light emitting element or the secondreflecting element are obtained from an image which has been imaged bythe imaging means, reference coordinates are obtained from thecoordinates of the first image, the orientation of the designating toolwith respect to the imaging means is obtained from the positionalrelationship of the reference coordinates and the second image, and thedesignating position on the display means is specified according to theorientation. Therefore, the size of the image which has been imaged isnot limited. Even if the distance between the imaging means and thedesignating tool is not constant, it is possible to specify thedesignating position on the screen and the demonstrator can move theposition. Furthermore, the screen corner of the image pick-up means canbe arbitrarily set, so the attachment location of the imaging means isnot limited, and adjustments can be easily performed.

[0188] In addition, a method is also provided wherein independentdesignating tool images which are separated from an image of a pluralitydesignating means into independent images are obtained from an imagewhich was imaged by the imaging means, a plurality of images ofdesignating means can be obtained from the independent designating toolimages which were divided into independent images, the orientation ofeach designating means relative to the imaging means is obtained foreach independent designating tool image, and the designating position onsaid display means is specified according to the orientation. Therefore,it is possible to simultaneously point out two or more locations, andsimultaneously perform input at two locations on the screen, such as oneselected by the demonstrator and one selected by a member of theaudience of the presentation.

What is claimed is:
 1. A remote coordinate input system for use with ascreen, comprising: an imaging device that images relative positionalrelationship between first light emitting elements and a second lightemitting element of a designator that includes at least three firstlight emitting elements and a second light emitting element that isarranged on an orthogonal axis to the plane which is composed of said atleast three first light emitting elements; a coordinate converter thatobtains an orientation of the designator with respect to said imagingdevice from an image which is imaged by said imaging device and convertsthe image to planar coordinates; an output device that outputs theplanar coordinates that are obtained by the coordinate converter; and adisplay that displays designating information on the screen based on theplanar coordinates that are obtained from said output device.
 2. Theremote coordinate input system of claim 1, each of the at least threefirst light emitting elements being respectively disposed at each vertexof an isosceles triangle, a base of the isosceles triangle that isformed by connecting two of the at least three first light emittingelements is substantially horizontally arranged.
 3. The remotecoordinate input system of claim 1, each of the at least three firstlight emitting elements being respectively arranged at each vertex of arhombus, one diagonal line of said rhombus being substantiallyhorizontally arranged.
 4. The remote coordinate input system of claim 1,further comprising: an operator disposed at the designator that providesoperating information; a modulator that modulates the at least threefirst light emitting elements or the second light emitting elementaccording to the operating information of the operator; and a lightreceiver that detects the modulation of the at least three first lightemitting elements and the second light emitting element.
 5. The remotecoordinate input system of claim 1, further comprising a hand detectorthat detects whether the designator is being held by a hand of a user,at least one of lighting and turning off of the light of the at leastthree first light emitting elements and the second light emittingelement being controlled by an output of said hand detector.
 6. A remotecoordinate input system for use with a screen, comprising: an imagingdevice that images relative positional relationship between firstreflecting elements and a second reflecting element of a designator thatincludes at least three first reflecting elements and a secondreflecting element that is arranged on an orthogonal axis to the planewhich is composed of said at least three first reflecting elements; anirradiating device that irradiates the at least three first reflectingelement and the second reflecting element; a coordinate converter thatobtains an orientation of the designator with respect to said imagingdevice from an image that is imaged by said imaging device and convertsthe image into planar coordinates; an output device that outputs theplanar coordinates that are obtained by the coordinate converter; and adisplay that displays designation information on the screen based on theplanar coordinates that are obtained from said output device.
 7. Theremote coordinate input system of claim 6, each of the at least threefirst reflecting elements being respectively disposed at each vertex ofan isosceles triangle, and a base of the isosceles triangle that isformed by connecting two of the at least three reflecting elements issubstantially horizontally arranged.
 8. The remote coordinate inputsystem of claim 6, each of the at least three first reflecting elementsbeing respectively arranged at each vertex of a rhombus, one diagonalline of said rhombus being substantially horizontally arranged.
 9. Aremote coordinate input system for use with a screen, comprising: animaging device that images relative positional relationship between ahollow disk-shaped first light emitting element and a second lightemitting element of a designator that includes a hollow disk-shapedfirst light emitting element and a second light emitting element that isarranged on an orthogonal axis to the plane which is composed of saidhollow disk-shaped first light emitting element; an irradiating devicethat irradiates the hollow disk-shaped first reflecting element and thesecond reflecting element; a coordinate converter that obtains anorientation of the designator with respect to said imaging device froman image which is imaged by said imaging device and converts the imageto planar coordinates; an output device that outputs the planarcoordinates that are obtained by the coordinate converter; and a displaythat displays designating information on the screen based on the planarcoordinates that are obtained from said output device.
 10. A remotecoordinate input method, comprising the steps of: obtaining a firstimage from a first light emitting element; obtaining a second image froma second light emitting element; obtaining a reference coordinate from acoordinate of said first image; obtaining an orientation of a designatorwith respect to an imaging device from a positional relationship betweenthe second image and the reference coordinate; and specifying adesignating position on a display according to said orientation.
 11. Theremote coordinate input method of claim 10, further comprising the stepsof: obtaining independent designating tool images in which an image of aplurality of designators are separated into images independant fromimages which have been imaged by said imaging device; obtaining anorientation of each designator with respect to the imaging device foreach independent designating tool image; and specifying designatedpositions on the display according to said orientations.
 12. A remotecoordinate input method, comprising the steps of: obtaining a firstimage from a first reflecting element; obtaining a second image from asecond reflecting element; obtaining a reference coordinate from acoordinate of said first image; obtaining an orientation of a designatorwith respect to an imaging device from a positional relationship betweenthe second image and the reference coordinate; and specifying adesignating position on a display according to said orientation.
 13. Theremote coordinate input method of claim 12, further comprising the stepsof: obtaining independent designating tool images in which an image of aplurality of designators are separated into independent images fromimages which have been imaged by said imaging device; obtaining anorientation of each designator with respect to the imaging device foreach independent designating tool image; and specifying designatedpositions on the display according to said orientations.